Pressure-responsive element

ABSTRACT

A pressure- and force-responsive element formed by etching a thin, flexible metal plate with a U-shaped cutout to define a planar tonguelike element supported at one end in cantilever fashion for bending motions about a hinge axis at the region of support. The etched plate forms one part of a multilayer sandwich construction which in one embodiment includes a thin layer of rubber to seal the periphery of the cantilever element so as to permit developing a differential pressure thereacross. Both force-balance and motion-balance configurations are included. The cantilever elements are used in an alarm device and a pneumatic timing unit.

United States Patent lnventor Philip H. Sanford Walpole, Mm. Appl. No 872,720 Filed Oct. 30, 1969 Patented July 20, 1971 Assignee The Foxboro Company Foxboro, Mm.

Continuation-impart of application Ser. No. 772,595, Nov. 1, 1968.

PRESSURE-RESPONSIVE ELEMENT ABSTRACT:

Primary Examiner-Samuel Scott Au0rneyBryan, Parmelee, Johnson & Ballinger A pressureand force-responsive element formed by etching a thin, flexible metal plate with a U-shaped cutout to define a planar tonguelike element supported at one end in cantilever fashion for bending motions about a hinge axis at the region of support. The etched plate forms one part of a multilayer sandwich construction which in one embodiment includes a thin layer of rubber to seal the periphery of the cantilever element so as to permit developing a differential pressure thereacross. Both force-balance and motion-balance configurations are included. The cantilever elements are used in an alarm device and a pneumatic timing unit.

PATENTEDJmzmsn sum 01 0F 1o 3.593.734

INVENTOR Philip H Sanford PATENTEU JUL20 I971 SHEET 0'4 0? 1O PATENTEDJUL20|9H 3593734 SHEET 05 [1F 104 l .2 92 H4 l I i 94 I T r /l\\ men ALARM A LOW ALARM SUB-SYSTEM SUB-SYSTEM PATENTED JUL 20 197i sum 07 or 1o PATENTEU JUL 20 I971 sum as or 10 PRESSURE-RESPONSIVE ELEMENT This application is a continuation-in-part of pending application Ser. No. 772,595, filed on Nov. 1, I968.

The invention relates primarily to apparatus, techniques and methods for the measurement and control of industrial process conditions such as temperature, flow rate and the like.

More particularly, the invention relates to improvements in pressure-responsive or force-responsive elements for performing a variety of functions including sensing of pressures, developing pneumatic control signals, altering the position of movable devices, and so forth. The invention has particular value in the art of pneumatic instruments, although in its broadest aspects it is not necessarily limited to that art.

In pneumatic instruments used for the measurement and/or control of industrial processes, a variety of different functions must be performed in an interrelated fashion for the purpose of accomplishing a desired end, such as that of maintaining a process condition at a preset level. Typical functions may include, for example, developing a force corresponding to a differential pressure, producing a pneumatic pressure signal proportional to an applied force, moving an operating device to a position determined by a pneumatic pressure signal, controllably altering a pneumatic signal to provide integral and derivative effects, etc. In prior pneumatic instrumentation systems, these and other required functions have been accomplished by means of various combinations of conventional diaphragms, bellows, restrictors, flapper-nozzle valves, and associated mechanical devices.

With the great growth in numbers of instruments used to control industrial processes, there has been an increasing demand for small-size instruments, so as to permit installation of more equipment in a given space. This is particularly important in process control rooms where virtually hundreds of instruments may be installed in panels for observation by operating personnel. To meet this need, instruments have in the recent past been constructed in compact configurations of the modular slim line" type. Although significant reductions in size have been effected by such compact packaging, still further reductions are needed, and can only be achieved through reducing the size of the individual components in an instrument, or by combining the functions of several components into a single component.

Pneumatic components of process instruments typically include force-responsive or pressure-responsive elements, such as conventional metallic diaphragms or bellows, and the size of these elements tends to dictate or significantly determine the size of the associated component. Reducing the size of these basic elements has presented a serious problem because such reduction in size ordinarily causes a corresponding increase in the spring rate or "stiffness of the element.

Any significant stiffness of a force or pressure-responsive element is not tolerable in many process control components because such stiffness tends to cause serious errors with changes in ambient temperature. In more detail, a change in ambient temperature generally will (as is well known) alter the dimension of various parts of the component, typically resulting in a shift of position of the pressure-responsive element with respect to the ground" of the device. With such a shift in position, there will be a corresponding change in the spring-reaction force developed by the element, and the magnitudeof this change in force will be proportional to the element stifiness."

This change in reaction force frequently represents an error-producing bias so that, as a rule, an element having a relatively large spring rate will cause a relatively large temperature error. In addition, the so-called gain" or sensitivity of a device is affected by its stiffness, i.e., with a higher spring rate, there will be a smaller gain.

Conventional metal diaphragms typically have a significantly high spring rate, although somewhat lower spring rates can be achieved with special convolutions or other shapes. Of course, the overall spring rate can be substantially reduced by stacking a series of diaphragms to form a conventional bellows, but this creates a bulky package. In addition, relatively long bellows (to achieve minimum spring rate) tend to buckle under certain internal pressure conditions.

In accordance with the present invention, there is provided a novel force- (or pressure-) responsive element having a very low spring rate, and yet adapted to be made quite small in size. Elements in accordance with this invention are capable, in certain configurations, of a relatively large output stroke. ln furtherance of another important aspect of this invention, such elements can be integrated into a multifunction component occupying very little space and adapted for economical manufacture.

In one preferred embodiment of the invention described hereinbelow in detail, a thin, flexible metal plate has portions cut out (as by etching) to define an interior tongue-shaped element supported at one end thereof in cantilever fashion. This element is subject to an applied force (or pressure) and in response to such force it deflects, with very small spring rate, about a hinge region adjacent the cantilever support so as to provide an output motion suited for controlling or actuating various output devices. Substantial output motions can be achieved in this manner with very low stress in the flexible material.

In another preferred embodiment of the invention, a thin spring plate is etched to present a number of different types of deflectable elements for performing difierent but interrelated functions. This composite plate is secured to a rigid support structure formed with conduits, grooves and other passages forpneumatically interconnecting the various forceor pressure-responsive elements. Such a plate also may be cut out to form still other types of operating elements including, for example, flexures for force bars, cantilevered springs, small apertures to serve as fluid flow restrictors, and may be combined with conventional fluidic (binary) devices.

Accordingly, it is an object of this invention to provide forceand/or pressure-responsive elements having significantly improved operating characteristics. It is a more specific object of this invention to provide such elements having a low spring rate and capable of performing precise functions in very little space. Another object of this invention is to provide forceand pressure-responsive elements capable of large output motions with relatively small stresses in the flexing material. A still further object of this invention is to provide improved means whereby a number of different pneumatic functions may be combined in a small-size component. Other objects, aspects and advantages of this invention will in part be pointed out in, and in part apparent from, the following description considered together with the accompanying drawings, in which:

FIGS. I through 3 are views of a single pressure-responsive element in accordance with this invention;

FIG. 4 shows in perspective a multielement spring plate;

FIGS. 5 through 10 are views of the separate parts of an alarm unit embodying concepts of the present invention;

FIG. 11 shows the assembled alarm unit, in perspective;

FIG. 12 is a diagrammatic presentation of the alarm unit;

FIG. 13 shows, in perspective, the pneumatic interconnections for the high-level subsystem of the alarm unit;

FIG. 14 is a section view of the alarm unit taken along line 14-14 of FIG. 1];

FIGS. 15a through 15g show an alternate embodiment; and

- FIG. 16 is a cross section through the embodiment of FIG. 15.

Referring now to FIGS: 1 and 2, there is shown a plate l0 of flexible spring steel for example 0.007 inch thick. This plate is cut out or blanked, by appropriate conventional techniques, to form an interior tonguelike element 12 supported at one end 14 in cantilever fashion by the surrounding portions of the plate. A thin rubber diaphragm 16 (shown with exaggerated thickness) is fitted beneath plate 10, serving as a fluidtight seal across the gap around the periphery of the flexible element 12. The plate and sealing diaphragm are held,

together with a gasket 18, by an outer support structure 20 which includes wall means forming a pressure chamber 22 beneath element I2.

As shown in FIG. 3, an increase in fluid (pneumatic) pressure beneath the element 12 forces it up. The resultant force can be considered as being applied to the center-of-pressure" of the selected geometric configuration, and this resultant force causes the element to bend smoothly about the region indicated as a hinged axis 24. Relatively low stress is developed in the element 12, even with quite substantial motions, and thus the device can operate over many cycles without failure.

Providing the diaphragm I6 with preformed slack convolution 26 particularly is beneficial in allowing a relatively long stroke of element 12 without developing large stresses in the rubber. The inclined wall 28 supports this slack portion as the stroke proceeds, and minimizes the area of the stretchable material exposed to the high pressures existing in chamber 22 when the element is stroked to its fullest extent, thereby tending to assure that the internal stresses in the rubber are maintained sufficiently low to prevent deterioration of its resilience.

Motion of the element 12 in response to pressure change can be used to control or actuate any suitable operating device, such as a switch or the like. It may be desirable to insure that the element does not flex (bend) anywhere except adjacent the hinge axis 24, and for this purpose a rigid stiffener 29 may be secured to the element. This stiffener may carry an actuating means, such as tab 29a adapted to perform some output controlling function.

The cantilevered element 12 may also be used in a forcebalance" configuration, rather than the motion-output configuration of FIG. 3. That is, means can be provided to apply opposed forces to the element from above and below, and

suitable means can be provided to maintain these forces in balance so that there is essentially no motion. As will be explained hereinbelow in more detail, sensing devices can be placed adjacent the element to detect any deflection resulting from a momentary unbalance of forces. Such sensing devices can be arranged to control feedback means so as to alter the pressure on one side of the element to maintain the applied forces in balance. Such a force-balance element preferably includes a stiffener 29 to assure a stable geometrical configuration (i.e. constant area) with changes in applied force.

Because the flexible element 12 is supported only at one end 14, rather than around its periphery as is a conventional diaphragm, the spring rate of element 12 for motion about the hinge axis 24 is quite low. That is, the spring reaction force developed in response to a stroke of given size is significantly less than in a conventional diaphragm. Thus, such a pressureresponsive element may be employed with significant advantage in instruments where temperature errors are an important constraint on the design criteria.

An important aspect of the present invention is the capability it provides for performing a number of interrelated functions in a small space. To this end, and referring now to FIG. 4, a single flexible metal plate 30 may be etched or otherwise blanked to form a large number of separate bendable elements 32-40 each supported at one edge or end thereof in cantilever fashion. Each of these elements is responsive to a pressure (or force), and the corresponding deflection of the respective element produces a control action effecting, or contributing to, a desired output result. Although these various elements 32--40 perform separate functions, these functions preferably are integrated in a system organization, as will be described below in detail, to achieve a desired end result. The component chosen to illustrate this aspect of the invention is an alarm" unit which provides an output indication (e.g. by energizing a light) when a measured process condition goes above a preset high level, or goes below a preset low level.

The plate 30 shown in FIG. 4 forms one layer of five-layer sandwich construction (FIGS. 10) including a rubber sealing diaphragm 50, a cork gasket 52, and outer support structures comprising body members 54 and 56. These latter members preferably are castings (e.g. the top one of plastic and the bottom one of metal) formed with a multiplicity of conduits, passages and grooves to conduct pneumatic pressure signals to and from the various individual flexible elements 32-40 of the spring plate.

Before describing in detail the manner in which the various elements of plate 30 are operably interconnected, an overall description of the system operation will first be presented, with the aid of the schematic diagram of FIG. 12, considered together with FIG. 4. Referring first to the upper right-hand comer of FIG. 12, the alarm unit includes a measurement bellows 60 to which is directed a pneumatic pressure signal corresponding in magnitude to the value of a measured process condition. This bellows produces a downward force against one end of element 32 (see also FIG. 4) which is supported for pivotal movement by a cantilevered arm 62 at one side of its central region.

Element 32 carries on its top surface a stiffener 64 and thus is adapted to serve as a force bar." Secured to the underside of this force bar are two baffles 66 and 68 adapted to seat on respective pneumatic control nozzles 70 and 72. An adjustable compression spring 74 and an adjustable tension spring 76 cooperatively combine with the bellows 60 to normally hold the baffles against the nozzles (as shown in broken outline) to maintain the nozzle passages closed so long as the measured process condition remains within the preset limits.

Control nozzle 70 is connected through a pair of series restrictors R2 and R1 to a source S of air under pressure, e.g. 20 p.s.i. With baffle 66 preventing airflow through the nozzle, there is no pressure drop across these restrictors, and the nozzle back pressure thus equals the supply pressure. This back pressure is directed through a passage 78 to a sealed chamber 80 beneath the end-cantilevered pressure-responsive element 34, and tends to push this element up.

Element 34 carries a stiffener 82 against which is applied to the downward force of a generally U-shaped spring, referred to herein as a C-spring." With full supply pressure of 20 p.s.i. in chamber 80, the force of this spring is overcome, and the element 34 thus is deflected to its upper position (as shown in solid outline) where a tab of magnetically soft steel 86 intercepts the flux from a magnet 88 and thereby prevents that magnet from actuating a conventional reed switch 90. Thus, in normal operating condition, this switch 90 is open, thereby preventing current from flowing from an electrical power source 92 to a high-level alarm indicator light 94.

When the measurement signal in bellows 60 goes above the high-level limit, the element 32 is tipped pivotally about the central (low-level) control nozzle 72 and lifts the baffle 66 away from its nozzle 70. This permits air to flow from supply source S, through the two series restrictors R1 and R2, and out the nozzle 70. The rate of flow is proportional to the distance between the nozzle and its baffle 66 (within the operating range of the nozzle), and thus is proportional to the amount by which the measured process condition has exceeded the preset level where the nozzle 70 first is uncovered. With air flowing through restrictors R1 and R2, the nozzle back pressure drops, thereby reducing the pressure in chamber 80 underneath the switch element 34. g Y

The alarm device includes a positive feedback circuit which produces a snap action in actuating the switch element 34. This positive feedback tends to hold the alarm actuated, and also produces a snap action in deactuating the alarm.

This positive feedback circuit can be traced through a connection from the junction between the two restrictors R1 and R2 to a closed chamber above the small cantilevered element 36. Chamber 100 also contains a spring I02 pressing element 36 towards engagement with a pneumatic nozzle 104 located in a second closed chamber I06 which is beneath element 36 and is connected to the air supply source S. This nozzle controls the flow of air to a feedback device, and thus will be referred to herein as the feedback nozzle.

. resulting flow of air through restrictor RI reduces the pressure in the chamber 100 above element 36, so that this element is forced up from feedback nozzle 104 by the supply pressure p.s.i.) in the lower chamber 106. Thus, air flows from the lower chamber out through the feedback nozzle, through a restrictor R3, and into a rubber capsule I08 which serves as the feedback device.

The airflow into capsule 108 causes it to inflate and press up against the pivoted element 32. The resulting motion of element 32 shifts the baffle 66 further away from the control nozzle 70 thereby further reducing the pressure in chamber I00, etc. The effect of this positive feedback is a snap-action movement of element 32 away from nozzle 70 to cause the pressure in chamber 80 to go immediately to its minimum level. Thereupon, the C-spring 84 forces element 34 down to remove shunt 86 from its flux-intercept position, so that switch 90 is closed to actuate the alarm indicator light 94.

The magnitude of the pressure in capsule 108 is set by an adjustable vent restrictor 110. The feedback force holds the control nozzle 70 open until the measurement signal in bellows 60 drops back a predetermined amount below the level at which the alarm was actuated, thereby providing a so-called dead-band of actuation. The size of this dead-band is adjustable by vent restn'ctor H0.

The alarm device disclosed herein includes both a highalarm subsystem (described hereinabove) and a low-alarm subsystem. The two subsystems devices are separated in FIG. 12 by a vertical line I12. The low-alarm subsystem energizes a light I14 when the measured process condition drops below a preset level. This low-alarm subsystem is activated by the right-hand control nozzle 72, when element 32 is tilted counterclockwise about control nozzle 70 in response to upward movement of bellows 60, and functions in a manner identical to that of thehigh-alarm subsystem. Thus no further description of the low-alarm subsystem will be presented herein, other than to note that it includes pressure-responsive elements 38 and 40 of the flexible etched plate 30, comparable to elements 34 and 36 already described.

Having now described in functional tenns the manner in which the alarm unit of FIGS. 5-10 operates, attentionnow will be directed to the particular constructional features which pennit such functions to be performed economically within a small space. To aid in explaining. these aspects of the invention, there has been included a perspective view (FIG. 13) showing a selected portion of the flexible plate 30 together with associated portions of the surrounding diaphragm 50, gasket 52, and the upper and lower body members 54, 56. These selected portions comprise the subsystem for producing the high-level alarm indication described functionally hereinabove. The plate 30, and the associated structure (FIGS. 5-10), also includes a subsystem for producing the low-level alarm function (outlined in the diagrammatic showing of FIG. I2), but this subsystem is substantially identical to the high-alarm subsystem and therefore will not be described in detail herein.

Referring now to the upper left-hand corner of FIG. 13, there is shown a conduit connection I20 which connects supply air pressure (S) to the alarm unit. This supply pressure is conducted through a fitting 122 in the upper body member 54, down through a vertical conduit 124 to a horizontal groove I26 extending in two directions along the undersurface of the upper body member. (Note: grooves and passages shown in solid outline are above the plate 30, while those shown in interrupted outline are below the plate.) Following the left-hand branch of groove 126, the supply pressure is applied through a hole 128 in gasket 52 (see FIG. 6) to a tiny pinhole 130 in plate 30 sewing asthe pneumatic flow restrictor RI referred to previously. This pinhole can be formed by piercing the metal plate 30 with a sharp instrument (like a sewing needle), or by known metal-drawing techniques. The pinhole may be only about 0.008 inch in diameter, depending upon the degree of restriction to be placed in the path of the airflow, and serves to produce a pressure drop for the purposes described hereinabove.

From the pinhole I30 (RI), the airflow path passes through a hole I32 in the rubber diaphragm 50 (see FIG. 8), and thence along a horizontal groove I34 in the upper surface of the lower body member 54 (see also FIG. 9). At the righthand end of this groove, the airflow path divides into two separate channels, going vertically upwards and downwards, respectively.

Considering first the upward flow channel, the path from groove I34 extends up through a hole I36 (FIG. 8) in the diaphragm 50, a coincident hole I38 in the plate 30, a hole (FIG. 6) in gasket 52, and thence to a small horizontal groove I42 in the bottom surface of the upper body member 54. This groove transports air under pressure to an adjacent position above a hole 144 (FIG. 6) in the gasket, leading down to a pinhole 146 (like pinhole I30) in the plate 30, and which performs the function of restrictor R2 in the alarm subsystem described hereinabove. On the lower side of this pinhole 146, the airflow path continues through a hole I48 in the diaphragm 50 (FIG. 8), and thence to a chamber 150 (FIG. 9) formed in the lower body member 56. This chamber has a hole 152 in its bottom to communicate with the pressure chamber 80 formed in the lower surface of the lower body member.

This lower pressure chamber 80 extends laterally throughout an area covering the entire lower surface of the switch element 34, and also communicates through a vertical passage 154 (formed in the lower body member 56) to the high-alarm control nozzle 70, previously referred to, located beneath the force bar element 32. Thus, when this force bar is lifted up away from nozzle 70, the resultant flow of air from the supply source S, through the path described above leading to the nozzle 70, causes a drop in pressure as it passes through both pinholes I30 and 146 (corresponding to restrictors RI and R2 previously described), so that there is a corresponding decrease in pressure in the chamber 80 beneath the flexible element 34. As mentioned hereinabove, when the pressure is sufficiently low, spring means above this element forces it down to its horizontal position to produce a switch closure which energizes an alarm light.

Returning now to the right-hand end of groove I34 previously referred to in body member 54, the airflow path from supply source S also extends downwardly through a hole 156 to a lateral groove 158 (see also FIG. 10) in the bottom surface of the lower body member. (Note: a solid cover plate 160 is secured in place over the bottom of this lower body member, so that the grooves formed in the lower surface are, in effect, closed conduits for the transmission of pneumatic pressures).

This groove 158 extends around to a vertical passage 162 leading up to a hole 164 in the diaphragm 50 (FIG. 8), a hole 166 in plate 30 (FIG. 7), and a hole 168 in the gasket 52 (FIG. 6) communicating with a lateral groove 170 (FIG. 5) in the upper body member 54. This groove I70 conducts the pressure signal a short distance to the pressure chamber I00 above the flexible element 36 of the plate 30. Thus, when air flows from supply source S through pinhole 130 (R1), the pressure in chamber 100 drops as described above with reference to FIG. I2.

Beneath this flexible element 36 is a second pressure chamber I06 (FIG. 9) which communicates through a hole 172 in the lower body member to a groove I74 (FIG. 10) in the bottom surface of the casting. This groove connects to a vertical passage I76 which is aligned with holes 178, I80 and 182 (FIGS. 8, 7 and 6 respectively) leading to the groove 126 (FIG. 5) carrying the supply air. Thus, chamber I06 is maintained at supply air pressure.

This chamber 106 contains the feedback nozzle I04 which, as described above with reference to FIG. I2, is controlled by the flexible-element 36 responding to the force above that element (ile. the air pressure in the upper chamber 100, in com bination with the force of spring 102). When the pressure in chamber 100 drops, the element 36 lifts up to uncover nozzle 104 to produce a flow of air into the nozzle, down a vertical passage 190, along a horizontal groove 192 in the bottom surface of the lower body member (FIG. and up through another vertical passage 194. From there, the airflow path passes through coincident holes 196, 198, 200 (FIGS. 8, 7 and 6) to a lateral passage 202 leading over to another set of coincident holes 204, 206, 208 (FIGS. 6, 7 and 8). The centerhole referred to above.

Diaphragm hole 208 is aligned with a vertical passage 210 in the lower body member 56 leading down to a lateral groove 212 (FIG. 10) which extends to another vertical passage 214 leading up to the rubber capsule 108. Lateral groove 212 also connects to an exit vent (not shown) which provides the adjustable restrictor 110 previously described.

Thus it will be evident that when the force bar element 32 first lifts up from the control nozzle 70, the flow of air from supply S through the passages described above, including restrictor pinhole 130 (R1), produces a reduced pressure in chamber 100. Element 36 shifts up to uncover feedback nozzle 104, so that thesupply pressure passes through restrictor 206 (R3) to capsule 108, to drive the force bar 32 completely away from nozzle 70. Thus the pressure in chamber 80 immediately drops to its minimum value, and switch element 34 thereupon is forced down by C-spring 84 to actuate switch 90 and energize indicator alarm 94.

. It will be apparent from the above description that the specific constructions disclosed herein are illustrative only, and that a variety of other embodiments can flow from the teachings herein. For example, flexible elements with different shapes can be utilized with advantage in different applications. When pressure sealing is required across the element, sealing means other than a rubber diaphragm can be used, including fabrics of various kinds. In some cases, sufficient sealing may be obtained by cutting a very narrow gap between the flexible element and the surrounding plate material, such that the leakage of air through the gap is so low as to assure an appropriate pressure differential between the two opposite sides of the flexible element. If a rubber sealing diaphragm is used, it may be planar, or it may be preformed with various configurations, such as a slack convolution, or a special shape matching the normal inclination of the corresponding flexible element. The plate containing the flexible elements may in some instances be-formed with apertures or the like to produce specialeffects (e.g. see rectangular holes 220 in FIG. 4 to reduce the spring rate of elements 36 and 40). The flexible elements can be used for proportioning action, such as to produce an operating effect (motion or the like) proportional to an input pressure or force, or may be used in an on-off (binary) configuration, e.g. as are the switch elements 34 and 38.

FIGS. and 16 illustrate another aspect of the invention wherein a cantilevered planar element (as described above) and a fluidic amplifier are integrated in a composite laminated sandwich arrangement to provide a unique component having important advantages. The term fluidic" as used herein refers to pneumatic amplifiers having no moving parts and which perform amplification functions through the application of tluidic dynamic principles. There are several different classes of such devices, prominent among which are wall atof the invention is a timing unit designed to provide an output pneumatic pressure pulse of predetermined (but adjustable) 206 of this set is a pinhole which serves as restrictor R3,

duration in response to an input trigger pulse. As shown in FIG. 15, this component comprises seven separatelayers fastened together, by conventional means such as suitable bolts and/or bonding techniques, to form a single sealed composite module. The central layer of the sandwich is a diaphragm 300 of suitable elastic material to provide interlayer sealing while permitting small motions of adjacent elements. Above and below this diaphragm are metal plates 302 and 304 appropriately formed with operating elements and interconnecting channels now to be described.

The plates 302 and 304 are formed, as by etching, with recessed cavities 306 and 308 defining back-to-back turbulence amplifiers. Each amplifier comprises a lead-in passage 310 (312), an interaction chamber 314 (316) with suitable control signal orifices along the sides, and an output passage 318 (320). The output passages connect to respective pressure-chambers 322 and 324 (see also FIG. 16) on opposite sides of a cantilevered flexible planar element 326, fundamentally similar to those previously described, but in this case the planar element comprises two identical metallic tongues 326a and 326b separated by the diaphragm 300.

Both amplifiers 306 and 308 are supplied with air under pressure which enters the timing unit through a pipe 330 at the bottom layer, base 332. This pipe connects to an internal conduit 344 extending transversely across the unit and supplying air to a pair of vertical conduits 336, 338 and a pair of nozzles 340, 342 formed with internal flow restrictors (not shown). The first vertical conduit 336 supplies air under reduced pressure to both turbulence amplifiers 306, 308. This connection can be traced from conduit 336 through a hole 344 in a layer 346 of sealing foil, a small restrictor hole 348 in the lower plate 304, a hole 350 in the diaphragm 300, a hole 352 in the upper plate 302, and a surface channel 354 (etched in the top surface of plate 302) which connects directly to the upper amplifier lead-in passage 310. Channel 354 also is connected through holes 356, 358 and 360 to the lower lead-in passage 312.

While the timer is in its quiescent normal state, the lower amplifier 308 is in on" condition. That is, there is a laminar flow of air from lead-in passage 312 to the output passage 320, causing the output pressure to be relatively high. Such an output pressure is referred to herein as "logical one." The output of this amplifier is interconnected with a control input of the upper amplifier 306 in such a way as to turn the second amplifier off" whenever the first amplifier is on." Specifically, output passage 320 is connected through an etched channel 370 and holes 372, 374, 376 to a control signal orifice 378. A logical one output pressure from the lower amplifier produces turbulence in the upper interaction chamber 314, and thereby causes a logical zero" (effectively atmospheric or zero" output pressure) to ensue from the upper amplifier.

The logical zero from the upper amplifier 306 and the logical one from the lower amplifier 308 are conducted respectively through output passages 318, 320 to the pressure chambers 322, 324. The resulting pressure differential between these chambers forces the planar element 326 upwards about its sealed hinge line 380 (as shown in interrupted outline in FIG. 16). This upward positioning of planar element 326 is transmitted through the hinge line 380 to force an integral companion planar element 382 to its down position. In this position, element 382 covers the orifice of nozzle 340 and thereby prevents any flow of air from that nozzle into the associated chamber 384. A second nozzle 386 in the roof of the chamber provides a vent to the outside and maintains atmospheric pressure in the chamber in the quiescent (nonactivated) state of the timer. The pressure in this chamber is conducted through an adjacent conduit 388 to a sealed tank 390 mounted on the top layer 392 (referred to herein as the cover"), for reasons which will be apparent shortly.

Now, to activate the timer, a pressure pulse trigger is supplied to either of two input pipes 394, 396 in the cover 392. One pipe 394 may be used for manually controlled input triggers, and the other 396 for automatically controlled (e.g.

periodic) input triggers. In either case, the input pressure pulse is conducted down through corresponding passageways to a respective control orifice 398 (400) in the lower amplifier interaction chamber 316. Application of such trigger pulse causes the air flow in that chamber to become turbulent, producing a logical zero" at the amplifier output.

This logical zero at the output of amplifier 308 is transmitted through channel 370 to the control signal orifice 378 of the upper amplifier 306. Since this logical zero is essentially atmospheric pressure, no air will flow into the chamber 314 from orifice 378 and thus the former turbulent conditions in chamber 314 will revert to laminar flow. Accordingly, the output of amplifier 306 goes to logical one.

This logical one serves as the output pulse of the timer unit, and is conducted from amplifier passage 318 up to an output pipe 402 from whence it may be directed to any desired utilization device. The output of amplifier 306 also is directed through an etched channel 317 and corresponding holes down to a control signal orifice 319 for the lower amplifier 308. Thus the logical one applied to this orifice assures that amplifier 306 will remain of! after the initial trigger pulse subsides.

It will be evident from the above description that the start of the timing pulse there is an instantaneous reversal of the differential pressure across planar element 326, causing this element to be forced down and thereby forcing the companion planar element 382 to its upper position (as shown in solid outline in FIG. 16). In this upper position, the element 382 opens the lower nozzle 340 and closes an upper nozzle 386. Accordingly, air begins to flow into chamber 384 through the lower nozzle 340.

The resulting increased pressure in chamber 384 produces a flow of air through conduit 388 to the tank 390. The pressure in this tank however rises relatively slowly, partly because of its large capacity, and also because the nozzle 340 is constructed with an interior flow restrictor.

As will be explained in more detail below, when the air pressure in tank 390 reaches a predetermined (but adjustable) level, the timer unit is caused to revert to its normal quiescent state, so that the pressure at output pipe 402 reverts to logical zero. Thus the output signal will be a pressure pulse of predetermined duration, initiated either by a manual input trigger or an automatic input trigger.

Turning now to details of this portion of the timer unit, the rising pressure level in tank 390 is sensed by a differential comparison device comprising a cantilevered planar element 404, similar to planar element 326 previously described. The chamber above element 404 is connected through a conduit 406 to the tank 390, so that element 404 continuously receives the tank pressure. This tank pressure is in turn continuously compared with the set" pressure in the chamber 408 below element 404, and means are operable to detect when the tank pressure has risen to a level equal to the set pressure.

The set pressure is controlled by an adjustable pressure divider circuit comprising a fixed restrictor in series with a variable restrictor. This pressure-divider circuit can be traced from the vertical supply conduit 338, up through a hole 410 in the sealing foil layer 346, a small (fixed) restrictor hole 412 in the lower metal plate 304, a hole 414 in the diaphragm 300, an etched channel 416 in the upper plate 302, back down through a hole 418 in the diaphragm 300 to an etched channel 420 in the lower plate 304, and up again through a hole 422 in this plate to an etched tapered (adjustable) circular restrictor channel 424 in the upper plate. To provide for adjustment of this latter restrictor, the cover 392 carries an adjustment knob 426 formed at one side with a vent hole 428 overlying the restrictor channel 424. By rotating knob 426, the vent hole is selectively movable to different positions along channel 424 so as to vary the amount of restriction presented to the flow of air vented to atmosphere.

Thus the pressure in etched channel 420 is variable, depending upon the setting of knob 426. This set" pressure is directed through a connecting etched channel 430 leading to the chamber 408 beneath cantilevered element 404.

At the start of the timing function, the set pressure in chamber 408 is substantially greater than the pressure (atmospheric) above element 404, so that this element is forced to its up position. Element 404 is formed integrally with a companion cantilevered element 432, on the other side of a sealed hinge line 434, so that while element 404 is up, the comparison element is down. When the latter element is down, it closes off lower nozzle 342, and leaves open an upper nozzle 436 which provides a vent to atmosphere. Thus, at the start of the timing pulse, the pressure in the associated chamber 438 will be atmospheric.

When the pressure above the element 404 has risen to the preadjusted set pressure in chamber 408, element 404 will be forced down, causing the companion element 432 to move up. This latter element thereupon closes the vent nozzle 436, and opens the supply nozzle 342, so that chamber 438 will immediately be pressurized to a significantly higher level.

This higher pressure (a logical one") is transmitted from chamber 438 through an etched channel 440 in the lower plate 304, and up through corresponding holes to a control signal orifice 442 in the upper amplifier 306. This logical one thus causes turbulence in the chamber 314, and the resulting diffusion of the airflow creates a logical zero at the amplifier output 318. The timing pulse at the output pipe 402 correspondingly goes to logical zero, signifying that the timing pulse has ended.

The logical zero in amplifier output 318 also is directed through etched channel 317 and corresponding holes to control signal orifice 319 to cut off the flow of air into the chamber 316 of amplifier 308. Thus this amplifier is turned on," and the timer unit returns to quiescent state. That is, the cantilevered element 382 is shifted down to open nozzle 386 and close nozzle 340. With the resultant venting of the chamber 384, the pressure above cantilevered element 404 returns to atmospheric, and that element thus moves up. This shifts down the companion element 432 to uncover vent nozzle 436 and close supply nozzle 342, so that the pressure in chamber 438 returns to atmospheric. The resulting shift from logical one to logical zero at control orifice 442 does not, however, tum amplifier 308 on, because in the meantime control orifice 378 had changed to logical one when the lower amplifier turned on. Thus, the upper amplifier 306 is held in off condition, pending the receipt of another initiating trigger pulse.

lclaim:

1. For use in pneumatically operated process instrument systems and the like, a pneumatic component comprising:

a thin plate formed with at least one opening shaped to define a peripheral portion and an interior element having substantial lateral dimensions relative to its thickness, said element being supported at one end thereof in cantilever fashion providing for pivoting about a hinge axis in the plane of the element where it joins said peripheral portion; and

pneumatic means adjacent one side of said element and interacting therewith to effect a desired operating result.

2. Apparatus as claimed in claim 1, wherein said plate is made of flexible material; said hinge axis being defined by a flexure region of said plate where said element is joined to the remaining portions of said plate.

3. Apparatus as claimed in claim 1, including means on both sides of said element for developing opposing pressure forces to be effectively balanced with essentially no motion of said element.

4. Apparatus as claimed in claim 3 wherein said plate is made of a springy metal; and rigid means fastened to one side of said element to serve as a stiffener and prevent distorting deflection of said element in the regions thereof alongside of said stiffener.

5. Apparatus as claimed in claim 1, wherein said pneumatic means comprises wall means defining a closed pressure chamber on one side of said element; and means to vary the pressure in said chamber to apply a controllable force to said element.

6. Apparatus as claimed in claim 5, including flexible seal means sealing off said opening along the periphery of said element to serve as a barrier to the flow of fluid pressure from one side to the other side of said element while permitting movement of said element transverse to the plane thereof.

7. Apparatus as claimed in claim 6, wherein said seal means comprises a thin, stretchable diaphragm having a slack portion along said periphery to provide for substantial motion of said element.

8. Apparatus as claimed in claim 7, including inclined wall means adjacent the edge of said peripheral slack portion to receive and support said seal means as the element is moved under pressure in said chamber. 9. Apparatus as claimed in claim I, wherein said pneumatic means comprises sensing means responsive to the positioning of said element and operable thereby to produce a corresponding pneumatic signal for transmission to an operating device.

10. Apparatus as claimed in claim 9, wherein said sensing means comprises a nozzle flapper.

11. For use in process instrument systems and the like, a component comprising:

a thin planar sheet of essentially nonstretchable material formed with an opening shaped to define a peripheral section and in an interior tonguelike'element, said element being supported at one end thereof in cantilever fashion providing for angular deflection about a hinge axis in the plane of said element, the edge portions of said element remote from said supported end being free for transverse movement as the element deflects about said hinge axis;

means adjacent one side of said element to apply thereto a fluid pressure'of controllable magnitude adapted to control deflection of said element about said axis; and

means adjacent said element and responsive to said movement thereof to effect a desired operating result.

12. A component as claimed in claim 11, including wall means forming an enclosed pressure chamber adjacent one side of said element; and means to direct to said chamber a fluid pressure to act on said element.

13. A component as claimed in claim ll including seal means in the peripheral region adjacent said element to serve as a barrier to fluid flow between the two sides of said element while permitting motion transverse to the plane thereof.

14. A component as claimed in claim 13, wherein said planar sheet is formed of metal, said seal means comprisinga second thin sheet of material having substantially greater flexibility than said metal.

15. A component as claimed in claim 14, wherein said second 'sheet is made of stretchable material. 7

16. A component as claimed in claim 14, wherein said second sheet is coextensive with said element and at least part of the metal sheet surrounding said opening; said second sheet being formed with a slack convolution portion in said peripheral region.

17. For use in process instrument systems and the like, a

component comprising:

a thin effective planar sheet apertured to define at least two interior elements, said elements being supported in cantilever fashion for pivotal movement at the respective region ofjoinder with the adjacent portions of said sheet;

means adjacent the free edges of said elements to restrict the flow of fluid through the apertures defining said elements while permitting said free edges to move transversely in response-to changes in pressure on the elements; and

fluid-operating means adjacent said planar sheet to interact with said two elements to provide desired operating results.

- 18. Apparatus as claimed in claim 17, wherein said pivotal movement comprises bending of said flexible plate material in said operat 20. Apparatus as claimed in claim 19, wherein said coupling means includes means forming passages interconnecting said elements.

2i. Apparatus as claimed in claim 19, wherein said coupling means comprises a rigid body member formed to provide at least one passageway communicating with at least one of said interior elements.

22. Apparatus as claimed in claim 19, wherein said coupling means includes means responsive to pressure conditions adjacent one of said elements and operable to apply a force to the other of said elements.

23. A component as claimed in claim 19, wherein said coupling means comprises a sheet of relatively rigid material secured to said planar sheet and formed with at least one channel groove cooperable with said planar sheet to define an enclosed passageway communicating laterally along said planar sheet.

24. A component as claimed in claim 19, including a thin sheet of resilient stretchable material overlying said planar sheet including at least one of said interior elements, said stretchable material serving to seal one side of said one element about its pivot region.

25. Apparatus for use in process instrumentation systems and the like, comprising:

a thin flat plate formed with an opening shaped to define an interior element having substantial lateral dimensions relative to its thickness, said element being supported at one end in cantilever style at the region of joinder to the adjoining portion of the plate to permit at least small pivotal movement thereof about a hinge axis adjacent the support;

means adjacent the free edges of said element to restrict the flow of fluid from one side to the other while permitting transverse movement of said free edges; and

operating means adjacent one side of said interior element to perform a desiredfunction in association with movement of said element;

said plate being formed with at least one additional opening defining a function element to serve an additional operation.

26. Apparatus as claimed in claim 25, wherein said opening is sufficiently small in cross section to serve as a restriction to the flow of fluid therethrough.

27. Apparatus as claimed in claim 25, including means coupling the spaces adjacent one side of said cantilever element to said function element.

28. Apparatus as claimed in claim 27 including means forming a pressure chamber on one side of said element; and coupling means connecting said restriction opening to said pressure chamber.

29. A fluid-pressure component comprising a sandwich construction including:

a thin plate apertured to define a plurality of distinct interior operation elements, at least one of said elements having a substantial area and being supported in cantilever fashion for pivotal movement about an axis at an end of that one element in the region of joinder thereof to an adjacent portion of said plate;

means adjacent the free edges of said one element to restrict the flow of fluid pressure through the aperture in said plate adjacent said one element while permitting transverse movement of said free edges; and

first and second support body members secured respectively on opposite sides of said plate, one of said body members being formed to define a pressure chamber adjacent one side of said cantilever element, whereby to apply a controllable pressure to that element.

30. Apparatus as claimed in claim 29, wherein one of said body members is formed to provide a pneumatic passage leading into the spaces adjacent at least one of said elements.

3]. Apparatus as claimed in claim 29, including sealing means in the form of an additional layer between said plate and one of said body members to prevent the flow of fluid all from one side of said one element around to the other side thereof.

32. A fluid-pressure component comprising a plurality of adjacent layers including a thin plate formed to define an interior element supported at one edge for pivotal deflection about a hinge axis at such edge in response to changes in applied force, said component further being formed in a region alongside said interior element to define an associated chamber within which fluid pressure can be developed;

at least one of said layers being provided with a cavity in a configuration defining fluidic amplifier means; and

said component being formed with passages for interconnecting said fluidic amplifier means with said chamber to transmit fluid pressure therebetween.

33. A component as claimed in claim 32, wherein said flexible plate is made of metal etched to define said fluidic amplifier means and said interior cantilever element.

34. A component as claimed in claim 32, wherein said fluidic amplifier cavity comprises a recess in said flexible plate.

35. A component as claimed in claim 34, wherein said interconnecting passages comprise recessed channels in the surface of said flexible plate.

36. A component as claimed in claim 35, wherein said fluidic amplifier is a turbulence amplifier the output conduit of which is connected to a recessed channel to direct the amplifier output pressure to said chamber; and sealing means around the periphery of said interior element to permit development of a differential pressure across said element.

37. A component as claimed in claim 32, including a sealing diaphragm forming one of said layers, said diaphragm being adjacent said flexible plate to provide sealing for said interior element to permit the development of a differential pressure.

38. A component as claimed in claim 37, wherein said component is formed to provide a second pressure chamber alongside said element on the opposite side thereof from said first chamber.

39. A component as claimed in claim 38, wherein said interconnecting passages provide communication between both said chambers and said fluidic amplifier means.

40. A component as claimed in claim 32, wherein pneumatic position-sensing means are mounted in said chamber and are responsive to movements of said interior element.

41. A component as claimed in claim 40, wherein said position-sensing means comprises a pneumatic nozzle through which air can flow; said element being located to control the air flow through said nozzle.

42. For use in pneumatically operated process instrument systems and the like, a component comprising:

a thin plate formed with an opening shaped to define a peripheral portion and an interior element integral with said peripheral portion at a region of joinder therebetween at one part of said element, said opening permitting movement of the edges of said element transversely with respect to the adjacent peripheral portion of said plate in response to the application to said element of a force tending to flex the element pivotally about said region of joinder;

means to restrict the flow of fluid through said opening so that the pivoting of said element may be controlled by variations in fluid pressure on one side thereof; and

means responsive to said pivotal movement of said element.

43. A component as claimed in claim 42, wherein said means to restrict the flow of fluid comprises a thin layer of flexible material overlying said opening.

44. A component as claimed in claim 43, wherein said layer of flexible material overlies said element in its entirety and at least part of said peripheral portion.

45. A component as claimed in claim 44, wherein said flexible material is also stretchable.

46. For use in pneumatically operated process instrument systems and the like, a component comprising:

a structure defining a chamber with an opening on one side thereof;

' a tonguelike element of springy bendable material positioned in said chamber opening and having one end secured to said structure in cantilever fashion for bending movement about said one end, said element being dimensioned to present between said structure and the edges of the element which are remote from said one end a gap permitting transverse movement of said element edges as the element bends about its support at said one end;

means to restrict fluid flow through said gap so that the bending of said element may be controlled by variations in fluid pressure in said chamber; and

means responsive to said bending movement of said element.

47. For use in pneumatically operated process instrument systems and the like, a component comprising:

a thin plate of flexible nonstretchable material formed with an opening shaped to define in said plate a peripheral portion surrounding an interior tonguelike element integral with said peripheral portion at a region of joinder therebetween at one end of said element, said opening permitting movement of the free edges of said element transversely with respect to the plane of said peripheral portion in response to the application to said element of a force tending to bend the element about said region of joinder;

means to restrict the flow of fluid through said opening so that the bending of said element about said region of joinder may be controlled by variations in fluid pressure on one side thereof; and

means responsive to said bending movement of said element.

48. For use in pneumatically operated process instrument systems and the like, a component comprising:

a rigid body member formed with a plurality of recesses adapted to serve as pressure chambers;

a thin plate of flexible nonstretchable material sealingly secured to said body member over said recesses, said plate being formed with at least one opening shaped to define in said plate a peripheral portion surrounding a plurality of interior tonguelike elements each opposite a respective recess in said body member to receive pressure therefrom, said elements being integral with said peripheral portion at respective regions of joinder at one end of each element, the opening defining each element pennitting movement of the free edges of the element transversely with respect to the plane of said peripheral portion as the element bends about its region of joinder to the peripheral portion in response to changes in pressure in the corresponding recess in the body member;

means to restrict the flow of fluid through the opening adjacent each said element; and

means responsive to said bending movement of said elements.

49. A component as claimed in claim 48, including a thin sheet of flexible material overlying said plate including said interior elements to prevent any fluid flow from said recesses to the opposite side of the plate while permitting the free edges of said elements to move transversely in response to changes in pressure in the respective recess.

50. For use in pneumatically operated process instrument systems and the like, a component comprising:

a thin plate apertured to form an effectively planar interior operator element and an outer peripheral section, said operator element being connected to said peripheral section by an integral segment of said thin plate which is located at a region between two adjacent portions of said interior element, said segment defining a hinge axis providing for pivotal deflection of said interior element with respect to said outer peripheral section; and

fluid-pressure means for applying a force to at least one of said element portions to effect pivotal deflection of said element about said axis.

51. A pressure device comprising:

a relatively stiff operator element presenting along one entire side thereof an effectively planar pressure-receiving ment about a hinge axis in the plane of said surface at one region thereof, said mounting means providing for pivotal movement of said element about said axis with said element surface at least substantially retaining its planar configuration so that a free end of said element remote from said axis moves transversely with respect to a line joining said free end and-said axis;

wall means cooperating with said pressure-receiving surface to define a pressure chamber the pressure of which is applied to said surface to develop a force thereon tending to pivot said operator about said hinge axis;

said wall means including portions extending along the peripheral edges of said element to restrict the flow of fluid from said one side of said element to the opposite side thereof while permitting said pivotal movement about said axis, whereby to provide for developing a differential pressure between the full areas of the two opposite sides of said element; and

means responsive to said movement of said operator element.

52. A pressure device comprising:

a structure defining a pressure chamber with an opening on one side thereof; 7 v

a tonguelike operator element of relatively stiff, generally planar material positioned in said chamber opening;

pivotal support means securing one end of said operator elementto said structure and providing for angular deflection of said element about an axis at said one end with a remote end moving towards or away from the interior of said chamber;

said operator element being dimensioned to present a gap means to restrict fluid flow through said gap so that the movement of said operator element may be controlled by variations in fluid pressure in said chamber; and means responsive to said pivotal movement of said element.

-. 53. A pressure device comprising:

a generally planar operator element presenting along opposite sides thereof respective opposed pressure-receiving surfaces of equal area;

mounting means for said operator element, said mounting means including means providing for pivotal movement of said element about an axis at one end of said element and parallel to the plane thereof, said mounting means further including means providing for a remote end of said element freedom for transverse movement with respect to a line between said remote end and said one end, whereby said remote end moves transversely as said element pivots about said axis;

means cooperating with one of said pressure-receiving surfaces to define a pressure chamber the pressure of which is applied to said entire surface to develop a force thereon tending to deflect said operator pivotally about said axis; and

means responsive to said movement of said operator element. 

1. For use in pneumatically operated process instrument systems and the like, a pneumatic component comprising: a thin plate formed with at least one opening shaped to define a peripheral portion and an interior element having substantial lateral dimensions relative to its thickness, said element being supported at one end thereof in cantilever fashion providing for pivoting about a hinge axis in the plane of the element where it joins said peripheral portion; and pneumatic means adjacent one side of said element and interacting therewith to effect a desired operating result.
 2. Apparatus as claimed in claim 1, wherein said plate is made of flexible material; said hinge axis being defined by a flexure region of said plate where said element is joined to the remaining portions of said plate.
 3. Apparatus as claimed in claim 1, including means on both sides of said element for developing opposing pressure forces to be effectively balanced with essentially no motion of said element.
 4. Apparatus as claimed in claim 3 wherein said plate is made of a springy metal; and rigid means fastened to one side of said element to serve as a stiffener and prevent distorting deflection of said element in the regions thereof alongside of said stiffener.
 5. Apparatus as claimed in claim 1, wherein said pneumatic means comprises wall means defining a closed pressure chamber on one side of said element; and means to vary the pressure in said chamber to apply a controllable foRce to said element.
 6. Apparatus as claimed in claim 5, including flexible seal means sealing off said opening along the periphery of said element to serve as a barrier to the flow of fluid pressure from one side to the other side of said element while permitting movement of said element transverse to the plane thereof.
 7. Apparatus as claimed in claim 6, wherein said seal means comprises a thin, stretchable diaphragm having a slack portion along said periphery to provide for substantial motion of said element.
 8. Apparatus as claimed in claim 7, including inclined wall means adjacent the edge of said peripheral slack portion to receive and support said seal means as the element is moved under pressure in said chamber.
 9. Apparatus as claimed in claim 1, wherein said pneumatic means comprises sensing means responsive to the positioning of said element and operable thereby to produce a corresponding pneumatic signal for transmission to an operating device.
 10. Apparatus as claimed in claim 9, wherein said sensing means comprises a nozzle flapper.
 11. For use in process instrument systems and the like, a component comprising: a thin planar sheet of essentially nonstretchable material formed with an opening shaped to define a peripheral section and in an interior tonguelike element, said element being supported at one end thereof in cantilever fashion providing for angular deflection about a hinge axis in the plane of said element, the edge portions of said element remote from said supported end being free for transverse movement as the element deflects about said hinge axis; means adjacent one side of said element to apply thereto a fluid pressure of controllable magnitude adapted to control deflection of said element about said axis; and means adjacent said element and responsive to said movement thereof to effect a desired operating result.
 12. A component as claimed in claim 11, including wall means forming an enclosed pressure chamber adjacent one side of said element; and means to direct to said chamber a fluid pressure to act on said element.
 13. A component as claimed in claim 11 including seal means in the peripheral region adjacent said element to serve as a barrier to fluid flow between the two sides of said element while permitting motion transverse to the plane thereof.
 14. A component as claimed in claim 13, wherein said planar sheet is formed of metal, said seal means comprising a second thin sheet of material having substantially greater flexibility than said metal.
 15. A component as claimed in claim 14, wherein said second sheet is made of stretchable material.
 16. A component as claimed in claim 14, wherein said second sheet is coextensive with said element and at least part of the metal sheet surrounding said opening; said second sheet being formed with a slack convolution portion in said peripheral region.
 17. For use in process instrument systems and the like, a component comprising: a thin effective planar sheet apertured to define at least two interior elements, said elements being supported in cantilever fashion for pivotal movement at the respective region of joinder with the adjacent portions of said sheet; means adjacent the free edges of said elements to restrict the flow of fluid through the apertures defining said elements while permitting said free edges to move transversely in response to changes in pressure on the elements; and fluid-operating means adjacent said planar sheet to interact with said two elements to provide desired operating results.
 18. Apparatus as claimed in claim 17, wherein said pivotal movement comprises bending of said flexible plate material in the region of joinder between each of said elements and an adjacent portion of said plate.
 19. Apparatus as claimed in claim 17, wherein said operating means comprises means to couple said two elements.
 20. Apparatus as claimed in claim 19, wherein said coupling means includes means formIng passages interconnecting said elements.
 21. Apparatus as claimed in claim 19, wherein said coupling means comprises a rigid body member formed to provide at least one passageway communicating with at least one of said interior elements.
 22. Apparatus as claimed in claim 19, wherein said coupling means includes means responsive to pressure conditions adjacent one of said elements and operable to apply a force to the other of said elements.
 23. A component as claimed in claim 19, wherein said coupling means comprises a sheet of relatively rigid material secured to said planar sheet and formed with at least one channel groove cooperable with said planar sheet to define an enclosed passageway communicating laterally along said planar sheet.
 24. A component as claimed in claim 19, including a thin sheet of resilient stretchable material overlying said planar sheet including at least one of said interior elements, said stretchable material serving to seal one side of said one element from the other side thereof while permitting ready movement about its pivot region.
 25. Apparatus for use in process instrumentation systems and the like, comprising: a thin flat plate formed with an opening shaped to define an interior element having substantial lateral dimensions relative to its thickness, said element being supported at one end in cantilever style at the region of joinder to the adjoining portion of the plate to permit at least small pivotal movement thereof about a hinge axis adjacent the support; means adjacent the free edges of said element to restrict the flow of fluid from one side to the other while permitting transverse movement of said free edges; and operating means adjacent one side of said interior element to perform a desired function in association with movement of said element; said plate being formed with at least one additional opening defining a function element to serve an additional operation.
 26. Apparatus as claimed in claim 25, wherein said opening is sufficiently small in cross section to serve as a restriction to the flow of fluid therethrough.
 27. Apparatus as claimed in claim 25, including means coupling the spaces adjacent one side of said cantilever element to said function element.
 28. Apparatus as claimed in claim 27 including means forming a pressure chamber on one side of said element; and coupling means connecting said restriction opening to said pressure chamber.
 29. A fluid-pressure component comprising a sandwich construction including: a thin plate apertured to define a plurality of distinct interior operation elements, at least one of said elements having a substantial area and being supported in cantilever fashion for pivotal movement about an axis at an end of that one element in the region of joinder thereof to an adjacent portion of said plate; means adjacent the free edges of said one element to restrict the flow of fluid pressure through the aperture in said plate adjacent said one element while permitting transverse movement of said free edges; and first and second support body members secured respectively on opposite sides of said plate, one of said body members being formed to define a pressure chamber adjacent one side of said cantilever element, whereby to apply a controllable pressure to that element.
 30. Apparatus as claimed in claim 29, wherein one of said body members is formed to provide a pneumatic passage leading into the spaces adjacent at least one of said elements.
 31. Apparatus as claimed in claim 29, including sealing means in the form of an additional layer between said plate and one of said body members to prevent the flow of fluid from one side of said one element around to the other side thereof.
 32. A fluid-pressure component comprising a plurality of adjacent layers including a thin plate formed to define an interior element supported at one edge for pivotal deflection about a hinge axis at such edge in response to changeS in applied force, said component further being formed in a region alongside said interior element to define an associated chamber within which fluid pressure can be developed; at least one of said layers being provided with a cavity in a configuration defining fluidic amplifier means; and said component being formed with passages for interconnecting said fluidic amplifier means with said chamber to transmit fluid pressure therebetween.
 33. A component as claimed in claim 32, wherein said flexible plate is made of metal etched to define said fluidic amplifier means and said interior cantilever element.
 34. A component as claimed in claim 32, wherein said fluidic amplifier cavity comprises a recess in said flexible plate.
 35. A component as claimed in claim 34, wherein said interconnecting passages comprise recessed channels in the surface of said flexible plate.
 36. A component as claimed in claim 35, wherein said fluidic amplifier is a turbulence amplifier the output conduit of which is connected to a recessed channel to direct the amplifier output pressure to said chamber; and sealing means around the periphery of said interior element to permit development of a differential pressure across said element.
 37. A component as claimed in claim 32, including a sealing diaphragm forming one of said layers, said diaphragm being adjacent said flexible plate to provide sealing for said interior element to permit the development of a differential pressure.
 38. A component as claimed in claim 37, wherein said component is formed to provide a second pressure chamber alongside said element on the opposite side thereof from said first chamber.
 39. A component as claimed in claim 38, wherein said interconnecting passages provide communication between both said chambers and said fluidic amplifier means.
 40. A component as claimed in claim 32, wherein pneumatic position-sensing means are mounted in said chamber and are responsive to movements of said interior element.
 41. A component as claimed in claim 40, wherein said position-sensing means comprises a pneumatic nozzle through which air can flow; said element being located to control the air flow through said nozzle.
 42. For use in pneumatically operated process instrument systems and the like, a component comprising: a thin plate formed with an opening shaped to define a peripheral portion and an interior element integral with said peripheral portion at a region of joinder therebetween at one part of said element, said opening permitting movement of the edges of said element transversely with respect to the adjacent peripheral portion of said plate in response to the application to said element of a force tending to flex the element pivotally about said region of joinder; means to restrict the flow of fluid through said opening so that the pivoting of said element may be controlled by variations in fluid pressure on one side thereof; and means responsive to said pivotal movement of said element.
 43. A component as claimed in claim 42, wherein said means to restrict the flow of fluid comprises a thin layer of flexible material overlying said opening.
 44. A component as claimed in claim 43, wherein said layer of flexible material overlies said element in its entirety and at least part of said peripheral portion.
 45. A component as claimed in claim 44, wherein said flexible material is also stretchable.
 46. For use in pneumatically operated process instrument systems and the like, a component comprising: a structure defining a chamber with an opening on one side thereof; a tonguelike element of springy bendable material positioned in said chamber opening and having one end secured to said structure in cantilever fashion for bending movement about said one end, said element being dimensioned to present between said structure and the edges of the element which are remote from said one end a gap permitting transverse movement of said element edgEs as the element bends about its support at said one end; means to restrict fluid flow through said gap so that the bending of said element may be controlled by variations in fluid pressure in said chamber; and means responsive to said bending movement of said element.
 47. For use in pneumatically operated process instrument systems and the like, a component comprising: a thin plate of flexible nonstretchable material formed with an opening shaped to define in said plate a peripheral portion surrounding an interior tonguelike element integral with said peripheral portion at a region of joinder therebetween at one end of said element, said opening permitting movement of the free edges of said element transversely with respect to the plane of said peripheral portion in response to the application to said element of a force tending to bend the element about said region of joinder; means to restrict the flow of fluid through said opening so that the bending of said element about said region of joinder may be controlled by variations in fluid pressure on one side thereof; and means responsive to said bending movement of said element.
 48. For use in pneumatically operated process instrument systems and the like, a component comprising: a rigid body member formed with a plurality of recesses adapted to serve as pressure chambers; a thin plate of flexible nonstretchable material sealingly secured to said body member over said recesses, said plate being formed with at least one opening shaped to define in said plate a peripheral portion surrounding a plurality of interior tonguelike elements each opposite a respective recess in said body member to receive pressure therefrom, said elements being integral with said peripheral portion at respective regions of joinder at one end of each element, the opening defining each element permitting movement of the free edges of the element transversely with respect to the plane of said peripheral portion as the element bends about its region of joinder to the peripheral portion in response to changes in pressure in the corresponding recess in the body member; means to restrict the flow of fluid through the opening adjacent each said element; and means responsive to said bending movement of said elements.
 49. A component as claimed in claim 48, including a thin sheet of flexible material overlying said plate including said interior elements to prevent any fluid flow from said recesses to the opposite side of the plate while permitting the free edges of said elements to move transversely in response to changes in pressure in the respective recess.
 50. For use in pneumatically operated process instrument systems and the like, a component comprising: a thin plate apertured to form an effectively planar interior operator element and an outer peripheral section, said operator element being connected to said peripheral section by an integral segment of said thin plate which is located at a region between two adjacent portions of said interior element, said segment defining a hinge axis providing for pivotal deflection of said interior element with respect to said outer peripheral section; and fluid-pressure means for applying a force to at least one of said element portions to effect pivotal deflection of said element about said axis.
 51. A pressure device comprising: a relatively stiff operator element presenting along one entire side thereof an effectively planar pressure-receiving surface; means mounting said operator element for pivotal movement about a hinge axis in the plane of said surface at one region thereof, said mounting means providing for pivotal movement of said element about said axis with said element surface at least substantially retaining its planar configuration so that a free end of said element remote from said axis moves transversely with respect to a line joining said free end and said axis; wall means cooperating with said pressure-receIving surface to define a pressure chamber the pressure of which is applied to said surface to develop a force thereon tending to pivot said operator about said hinge axis; said wall means including portions extending along the peripheral edges of said element to restrict the flow of fluid from said one side of said element to the opposite side thereof while permitting said pivotal movement about said axis, whereby to provide for developing a differential pressure between the full areas of the two opposite sides of said element; and means responsive to said movement of said operator element.
 52. A pressure device comprising: a structure defining a pressure chamber with an opening on one side thereof; a tonguelike operator element of relatively stiff, generally planar material positioned in said chamber opening; pivotal support means securing one end of said operator element to said structure and providing for angular deflection of said element about an axis at said one end with a remote end moving towards or away from the interior of said chamber; said operator element being dimensioned to present a gap between said structure and the edges of the element which are remote from said one end, said gap permitting transverse movement of said element edges with respect to the plane of said opening as the element pivots about its support at said one end; means to restrict fluid flow through said gap so that the movement of said operator element may be controlled by variations in fluid pressure in said chamber; and means responsive to said pivotal movement of said element.
 53. A pressure device comprising: a generally planar operator element presenting along opposite sides thereof respective opposed pressure-receiving surfaces of equal area; mounting means for said operator element, said mounting means including means providing for pivotal movement of said element about an axis at one end of said element and parallel to the plane thereof, said mounting means further including means providing for a remote end of said element freedom for transverse movement with respect to a line between said remote end and said one end, whereby said remote end moves transversely as said element pivots about said axis; means cooperating with one of said pressure-receiving surfaces to define a pressure chamber the pressure of which is applied to said entire surface to develop a force thereon tending to deflect said operator pivotally about said axis; and means responsive to said movement of said operator element. 